3
  Li  
6.941000
Lithium

Name: Lithium
Symbol: Li
Atomic Number: 3
Atomic Weight: 6.941000
Family: Alkali Metals
CAS RN: 7439-93-2
Description: A silvery white/grey metal.
State (25C): Solid
Oxidation states: +1

Molar Volume: 13 cm3/mole
Valence Electrons: 2s1

Boiling Point:  1615.15K, 1342C, 2448F
Melting Point:
453.85K, 180.7C, 357.3F
Electrons Energy Level: 2, 1
Isotopes: 7 + 2 Stable
Heat of Vaporization: 145.92 kJ/mol
Heat of Fusion: 3 kJ/mol
Density: 0.534 g/cm3 @ 300K
Specific Heat: 3.6 J/gK
Atomic Radius: 2.05
Ionic Radius: 0.76
Electronegativity: 0.98 (Pauling); 0.97 (Allrod Rochow)
Vapor Pressure: 1.63E-08 Pa @ 180.7C
1
H
1.007
Petalite, LiAl(Si2O5)2, which contains Lithium, was first discovered by the Brazilian scientist Jose Bonifacio de Andrade e Silva toward the end of the 1700s on a trip to Sweden.  Lithium was discovered by Johan August Arfwedson in 1817.  Arfwedson found the new element within the minerals Spodumene and Lepidolite in the Petalite ore that he was analyzing during a routine investigation of some minerals from a mine on the island Uto in Sweden.  In 1818 Christian Gmelin was the first to observe that Lithium salts give a bright red color in flame.  Both men tried and failed to isolate the element from its salts.

The element was not isolated until William Thomas Brande and Sir Humphry Davy later used electrolysis on Lithium Oxide (Li2O) in 1818.  Robert Bunsen and Matiessen isolated larger quantities of the metal by electrolysis of Lithium Chloride in 1855.  Commercial production of Lithium metal was achieved in 1923 by the German company Metallgesellschaft through using electrolysis of molten Lithium Chloride and Potassium Chloride.  It was apparently given the name "Lithium" (Greek (lithos), meaning "stone") because it was discovered from a mineral while other common alkali metals were first discovered from plant tissue.

It is less dense than water (with which it reacts) and forms a black oxide in contact with air.

Lithium in its pure form does not occur naturally on Earth.  It is a soft, silver white metal.  Lithium reacts with Oxygen from the air to form black Lithium Oxide, Li2O.   It therefore has to be stored under the cover of oil stop this oxidation reaction from occurring.  It tarnishes and oxidizes very rapidly in air and water.

Today, larger amounts of the metal are obtained through the electrolysis of Lithium Chloride (LiCl). Lithium is not found free in nature and makes up only 0.0007% of the earth's crust.

3
Li
6.941
11
Na
22.98
19
K
39.09
37
Rb
85.46
55
Cs
132.9
87
Fr
223.0

Characteristics

In its mineral forms it accounts for only 0.0007% of the earth's crust.  It compounds are used in certain kinds of glass and porcelain products. More recently Lithium has become important in dry-cell batteries and nuclear reactors. Some compounds of Lithium have been used to treat manic depressives.

1s2 2s1

In compounds Lithium (like all the alkali metals) has a +1 charge and has a relatively low melting point (181oC).

Lithium is one of only four elements theorized to have been created in the first three minutes of the universe through a process called Big Bang nucleosynthesis.  It is in group 1 of the periodic table, among the alkali metals and is the lightest solid element.

Lithium metal is used primarily in heat-transfer applications, batteries (mainly cell phone and camera batteries), household appliances such as toasters and microwaves, and in high performance alloys such as those used for aircraft construction. Lithium compounds are used pharmacologically as a class of mood stabilizing drugs, a neurological effect of the Lithium ion Li+.

Though in group 1, Lithium also exhibits properties of the alkaline-Earth metals in group 2.  Like all alkali metals, it has a single valence electron, and will readily lose this electron to become a positive ion.  Because of this, Lithium reacts easily with water and does not occur as the free element on Earth.  Nevertheless, it is less reactive than the chemically similar Sodium, Na.

Lithium is soft enough to be cut with a knife, though this is significantly more difficult to do than cutting Sodium.  The fresh metal is silver in color, rapidly tarnishing black in air.  Lithium has only about half the specific gravity of water, giving solid metal Lithium sticks the odd heft of a light/medium wood, such as pine.  The metal floats highly in hydrocarbons due to its low density, and jars of Lithium in the laboratory are typically composed of black-coated sticks held down in hydrocarbon mechanically by the lid of the jar and other sticks.

When placed over a flame, Lithium gives off a striking crimson color, but when it burns strongly, the flame becomes a brilliant white. Lithium will ignite and burn when exposed to water and water vapours in Oxygen.  It is the only metal that reacts with nitrogen at room temperature.  Lithium has a high specific heat capacity, 3582 J/(kgK), and a great temperature range in its liquid form, which makes it a useful chemical.

80px-Flammable.jpg (2186 bytes) Lithium metal is flammable and potentially explosive when exposed to air and especially water, though it is far less dangerous than other alkali metals in this regard.  The lithium-water reaction at normal temperatures is brisk but not violent.  Lithium fires are difficult to extinguish, requiring special chemicals designed to smother them.

Lithium metal, due to its alkaline tarnish, is a corrosive and requires special handling to avoid skin contact.  Breathing Lithium dust or Lithium compounds (which are often alkaline) can irritate the nose and throat; higher exposure to Lithium can cause a build-up of fluid in the lungs, leading to pulmonary edema.  The metal itself is usually less a handling hazard than the caustic hydroxide produced when it is in contact with moisture.  Lithium should be stored in a non-reactive compound such as naphtha or a hydrocarbon.

In humans Lithium compounds have not been found to play a natural biological role; large amounts are slightly toxic.  Lithium appears to be an essential trace element for goats, and possibly rats, suggesting a role in humans by analogy.  However, the essentiality of ultratrace mineral in humans is far more difficult to determine, due to the difficulty and ethical issues involved with the experiments, which involve total isolation from the environment, and unpalatable semi-synthetic foods.

When used as a drug, blood concentrations of Li+ must be carefully monitored.

Occurrence

On Earth, Lithium is widely distributed, but because of its reactivity does not occur in its free form.  In keeping with the origin of its name, Lithium forms a minor part of almost all igneous rocks and is also found in many natural brines.  Lithium is the thirty-first most abundant element, contained particularly in the minerals Spodumene, Lepidolite, Petalite, and Amblygonite.  On average, Earth's crust contains 65 parts per million (ppm) Lithium.

Since the end of World War II, Lithium metal production has greatly increased.   The metal is separated from other elements in igneous mineral such as those above, and is also extracted from the water of mineral springs.

The metal is produced electrolytically from a mixture of fused Lithium and Potassium Chloride.  In 1998 it was about $43 per pound ($95 per kilogram).

Chile is currently the leading Lithium metal producer in the world, with Argentina following.  Both countries recover the Lithium from brine pools.  In the United States Lithium is similarly recovered from brine pools in Nevada.

Applications

Many uses have been found for lithium and its compounds. Lithium has the highest specific heat of any solid element and is used in heat transfer applications. It is used to make special glasses and ceramics, including the Mount Palomar telescope's 200 inch mirror. Lithium is the lightest known metal and can be alloyed with Aluminum, Copper, Manganese, and Cadmium to make strong, lightweight metals for aircraft. Lithium Hydroxide (LiOH) is used to remove Carbon Dioxide from the atmosphere of spacecraft. Lithium Stearate (LiC18H35O2) is used as a general purpose and high temperature lubricant. Lithium Carbonate (Li2CO3) is used as a drug to treat manic depression disorder.

Because of its specific heat capacity, the highest of all solids, Lithium is often used in heat transfer applications.

It is an important battery cathode material, used in Lithium Ion batteries because of its high electrochemical potential.  The Lithium Ion cell is lighter than a standard dry cell and produces twice the voltage (3 volts rather than 1.5).

Large quantities of Lithium are also used in the manufacture of organolithium reagents, especially n-butyllithium which has many uses in fine chemical and polymer synthesis.

Medical Use

Lithium salts such as Lithium Carbonate (Li2CO3), Lithium Citrate, and Lithium Orotate are mood stabilizers.  They are used in the treatment of bipolar disorder, since unlike most other mood altering drugs, they counteract both mania and depression.  Lithium can also be used to augment other antidepressant drugs.   It is also sometimes prescribed as a preventive treatment for migraine disease and cluster headaches

The active principle in these salts is the Lithium ion Li+, which interacts with the normal function of Sodium Ions to produce numerous changes in the neurotransmitter activity of the brain.  Therapeutically useful amounts of Lithium are only slightly lower than toxic amounts, so the blood levels of Lithium must be carefully monitored during treatment.

Other Uses

6Li + n rarrow.gif (63 bytes) 4He + 3T

2Li2O2 + 2CO2 rarrow.gif (63 bytes) 2Li2CO3 + O2.

Market Trend

Prices of Lithium Carbonate rose by 20% in 2005 and growth of up to 25% is forecast by Roskill Consulting Group for 2006, bringing prices back to the peak levels seen prior to SQM's entry into the market in 1996.  New capacity due on-stream in Chile, Argentina and China is forecast to alleviate the upward pressure on prices after 2007.

Consumption of Lithium increased by 4–5% per year between 2002 and 2005, driven by demand in Lithium secondary batteries.  Batteries accounted for 20% of total consumption in 2005, a rise from under 10% in 2000.

Continued expansion in the portable electronic products market and commercialisation of hybrid electric vehicles using Lithium batteries suggest growth of up to 10% per year in Lithium Carbonate consumption in this market through 2010.

Between 2002 and 2005, Lithium minerals production rose by 7% per year to reach 18,800 tons Li. Chile and Australia account for over 60% of total output.  FMC Lithium of the USA, Chemetall of Germany and SQM of Chile continue to dominate production of downstream lithium chemicals.

China may emerge as a significant producer of brine-based Lithium Carbonate towards the end of this decade.  Potential capacity of up to 45,000 tons per year could come on-stream if projects in Qinghai province and Tibet proceed.

Regulation

Some jurisdictions limit the sale of Lithium batteries, which are the most readily available source of Lithium metal for ordinary consumers.  Lithium can be used to reduce Pseudoephedrine and Ephedrine to Methamphetamine in the Birch Reduction Method, which employs solutions of alkali metals dissolved in Anhydrous Ammonia.  However, the effectiveness of such restrictions in controlling illegal production of Methamphetamine remains indeterminate and controversial.

Carriage and shipment of some kinds of Lithium batteries may be prohibited aboard certain types of transportation (particularly aircraft), because of the ability of most types of Lithium batteries to fully discharge very rapidly when short-circuited, leading to overheating and possible explosion.  However, most consumer Lithium batteries have thermal overload protection built-in to prevent this type of incident, or their design inherently limits short-circuit currents.

Lithium is a component for thermonuclear weapons (so called "Hydrogen Bombs") and applications of Lithium for this purpose in the nuclear weapons industry is pursued in developing nuclear powers like India, and presumably others.

Compounds

Lithium Carbonate, Li2CO3 Lithium Peroxide, Li2O2
Lithium Hydroxide, LiOH Lithium Stearate, LiC18H35O2
Lithium Citrate Lithium Orotate
Lithium Chloride, LiCl Lithium Bromide, LiBr
Lithium Niobate Petalite, LiAl(Si2O5)2
Lithium Oxide, Li2O  

Isotopes

Naturally occurring Lithium is composed of two stable isotopes  6Li and 7Li, the latter being the more abundant (92.5% natural abundance).  Seven radioisotopes have been characterized, the most stable being 8Li with a half-life of 838 ms and 9Li with a half-life of 178.3 ms.  All of the remaining radioactive isotopes have half-lives that are shorter than 8.6 ms.  The shortest-lived isotope of lithium is 4Li which decays through proton emission and has a half-life of 7.58043x10-23 seconds.

7Li is one of the primordial elements, or, more properly, primordial isotopes, produced in Big Bang nucleosynthesis (a small amount of 6Li is also produced in stars).  Lithium isotopes fractionate substantially during a wide variety of natural processes, including mineral formation (chemical precipitation), metabolism, and ion exchange.  Lithium Ion substitutes for Magnesium and Iron in octahedral sites in clay minerals, where 6Li is preferred to 7Li, resulting in enrichment of the light isotope in processes of hyperfiltration and rock alteration.

Isotope Atomic Mass Half-Life
Li4 4.027 7.58043 x 10-23 seconds
Li5 5.0125 3.04733 x 10-22 seconds
Li6 6.0151 Stable
Li7 7.016 Stable
Li8 8.0225 838 ms
Li9 9.0268 178.3 ms
Li10 10.0355 3.8091710-22 seconds
Li11 11.0438 8.5 ms
Li12 12.05 < 10 nanoseconds

Precautions

40px-Skull_and_crossbones.svg.jpg (1420 bytes) As noted earlier, Lithium metal, due to its alkaline tarnish, is a corrosive and requires special handling to avoid skin contact.  Breathing Lithium dust or Lithium compounds (which are often alkaline) can irritate the nose and throat; higher exposure to Lithium can cause a build-up of fluid in the lungs, leading to pulmonary edema.

Lithium Data

 

Atomic Structure

Atomic Radius (): 2.05
Atomic Volume cm3/mol : 13.1cm3/mol
Covalent Radius: 1.23
Crystal Structure: Cubic body centered
Ionic Radius: 0.76

Chemical Properties

Electrochemical Equivalents: 0.259 g/amp-hr
Electron Work Function: 2.9eV
Electronegativity: 0.98 (Pauling); 0.97 (Allrod Rochow)
Heat of Fusion: 3 kJ/mol
Incompatibilities: water, acids, oxidizing agents
First Ionization Potential: 5.392
Second Ionization Potential: 76.638
Third Ionization Potential: 122.451
Valence Electron Potential(-eV): 19
Ionization Energy (eV): 5.392 eV

Physical Properties

Atomic Mass Average: 6.941
Boiling Point: 1615.15K, 1342C, 2448F
Melting Point: 453.85K, 180.7C, 357.3F
Heat of Vaporization: 145.92 kJ/mol
Coefficient of Lineal Thermal Expansion/K-1: 56E-6
Electrical Conductivity: 0.108 106/cm
Thermal Conductivity: 0.847 W/cmK
Density: 0.534 g/cm3 @ 300K
Elastic Modulus (Bulk): 11/GPa
Elastic Modulus (Rigidity): 4.24/GPa
Elastic Modulus Youngs: 4.91/GPa
Enthalpy of Atomization: 160.7 kJ/mole @ 25C
Enthalpy of Fusion: 3 kJ/mole
Enthalpy of Vaporization: 134.7 kJ/mole
Hardness Scale (Brinell): unknown
Hardness Scale (Mohs): 0.6
Hardness Scale (Vickers): unknown
Flammability Class: Flammable solid
Molar Volume: 13 cm3/mole
Optical Reflectivity: unknown
Optical Refractive Index: unknown
Relative Gas Density (Air=1): unknown
Specific Heat: 3.6 J/gK
Vapor Pressure: 1.63E-08 Pa @ 180.7C
Estimated Crustal Abundance: 2.0101 milligrams per kilogram
Estimated Oceanic Abundance:
1.810-1 milligrams per liter


(Gr. lithos, stone) Discovered by Arfvedson in 1817. Lithium is the lightest of all metals, with a density only about half that of water. It does not occur free in nature; combined is is found in small units in nearly all igneous rocks and in the waters of many mineral springs. Lepidolite, spodumeme, petalite, and amblygonite are the more important minerals containing it. Lithium is presently being recovered from brines of Searles Lake, in California, and from those in Nevada. Large deposits of quadramene are found in North Carolina. The metal is produced electrolytically from the fused chloride. Lithium is silvery in appearance, much like Na and K, other members of the alkali metal series. It reacts with water, but not as vigorously as sodium. Lithium imparts a beautiful crimson color to a flame, but when the metal burns strongly, the flame is a dazzling white. Since World War II, the production of lithium metal and its compounds has increased greatly. Because the metal has the highest specific heat of any solid element, it has found use in heat transfer applications; however, it is corrosive and requires special handling. The metal has been used as an alloying agent, is of interest in synthesis of organic compounds, and has nuclear applications. It ranks as a leading contender as a battery anode material as it has a high electrochemical potential. Lithium is used in special glasses and ceramics. The glass for the 200-inch telescope at Mt. Palomar contains lithium as a minor ingredient. Lithium chloride is one of the most lyproscopic materials known, and it, as well as lithium bromide, is used in air conditioning and industrial drying systems. Lithium stearate is used as an all-purpose and high-temperature lubricant. Other lithium compounds are used in dry cells and storage batteries. The metal is priced at about $300/lb.

Source: CRC Handbook of Chemistry and Physics, 1913-1995. David R. Lide, Editor in Chief. Author: C.R. Hammond